[Code gen] Detach execute node function from __init__.py to every node class to make different treating of thresholds and weights possible

[Code gen] Commit of current state of work, test cpp file to check syntax for implementing weights and threshold activation

[Test finn hls onnx graph] Deleted obsolete .onnx file and changed test script to not produce .onnx anymore

[Structure] Integrated previous code generation for single node into new structue (as functions in streaminmaxpool.py) and deleted old file

[Docker] Modified run-docker.sh to check for an environmental variable VIVADO_PATH to set the connection to the include directory